1. Field of the Invention
The present invention relates to a technology field enabling a voice call between two parties on the Internet by using a general-purpose computer such as a personal computer (PC) as an IP (Internet Protocol) telephone terminal.
2. Related Art
In recent years, an IP telephone system has been focused on in the usage of VoIP (Voice over IP) technology in realizing voice call by means of IP packets, with considerable reasons such as reducing call toll for the public stationed telephones and so on. In the functional aspect of this IP telephone system, various proposals are made.
For example, Japanese Unexamined Patent Publication No. JP-A-2003-169135, which is hereby incorporated for reference, discloses a VoIP communication system, in which IP telephone terminals for conducting a VoIP call can mutually call by designating their telephone numbers without noticing their IP addresses being dynamically assigned at the time of dial-up connection, and in which it is assured that an IP address of a called destination party has the correct IP address when the called IP telephone terminal is inquired with a GateKeeper by designating the telephone number.
However, in such an IP telephone system, it is generally necessary to prepare an IP telephone terminal hardware or an adapter having VoIP functionality. Therefore, users should prepare a new hardware by spending a further expense. Further, a user is required to install to a PC for example an application with VoIP call functionality. For doing this, it is necessary for the user to do a difficult environmental configuration setup on such Windows (registered trade mark) operating system. However, the users like elderly people, in particular, feel it hard to use such a system.